Wireless communications networks may incorporate multiple wireless systems to provide communications services. In one example, a wireless communications network includes a public wireless communications system and a private wireless communication system that cooperate to provide communication services to a common set of subscribers. A private wireless communication system is usually limited to serving subscribers within a coverage area required for a business or governmental entity. For example, a private communications system may serve an office complex or a corporate campus of a commercial entity. A public wireless communications system is accessible to qualified subscribers from the general public and other subscribers who may have access to the private wireless communications system.
A wireless data server ordinarily extends e-mail messaging to subscribers of a public wireless communications system. The conventional wireless data server typically supports message notification and delivery for mobile subscribers. If the subscriber roams to the private wireless communications system from the public wireless communications system, the private wireless communications system often does not support the wireless data server in servicing the subscriber. Accordingly, the roaming subscriber may miss data messages, such as e-mail messages, while active on the private communications system.
In another example, a wireless communications network includes multiple public wireless systems that cooperate to provide communication services to a common set of subscribers who roam from the coverage area of a home public wireless system to a visited public wireless system. The home wireless data server may provide wireless data service to the visiting mobile subscriber visiting on a visiting wireless system. However, the home wireless data server consumes inter-system signaling resources to provide such a message redirection service. The redirection of data messages may be delayed until inter-system signaling capacity is available, rather than providing real-time or timely redirection of data messages. Thus, a need exists for directing a data message in a communications network to enable a roaming subscriber to reliably and timely receive data messages through a private communications system or a public communications system.